Process for transfer dyeing of synthetic textile materials

ABSTRACT

PROCESS FOR COLOURING SYNTHETIC TEXTILE MATERIALS WHICH COMPRISES APPLYING A WATER-INSOLUBLE DYESTUFF TO THE TEXTILE MATERIAL WHICH IS THEN SUBJECTED TO A DRY HEAT TREATMENT AT A PRESSURE LESS THAN ATMOSPHERIC PRESSURE.

United States Patent Office 3,702,752 Patented Nov. 14, 1972 US. Cl. 82.5 3 Claims ABSTRACT OF THE DISCLOSURE Process for colouring synthetic textile materials which comprises applying a water-insoluble dyestuff to the textile material which is then subjected to a dry heat treatment at a pressure less than atmospheric pressure.

This invention relates to a coloration process and more particularly to a process for coloring synthetic textile materials.

It is well known to color synthetic textile materials or unions containing synthetic textile materials, by applying to the textile material an aqueous dispersion of a dyestuff, drying the textile material and then subjecting it to a dry heat treatment involving baking or steaming using superheated steam. During this dry heat treatment transfer of the dyestuff takes place within the synthetic textile material, or, in the case of unions of synthetic textile materials with protein or cellulose textile materials, transfer of the dyestuff takes place from the protein or cellulose (which are preferentially colored in the initial stages) to the synthetic textile materials. However, during the past few years it has been found necessary to produce dyestuffs for synthetic textile materials which have much higher fastness to heat treatments such as are used in pleating operations, and it has been found that such dyestuffs are not so readily transferred so that it has become increasingly difficult to obtain satisfactory coloration of the synthetic textile materials.

It has now been found that this difficulty can be overcome by carrying out the whole or part of the dry heat treatment at pressures less than atmospheric pressure.

According to the invention there is provided a process for coloring synthetic textile materials or unions containing synthetic textile materials which comprises applying a water-insoluble dyestuff to the textile material and then subjecting the textile material to a dry heat treatment at a pressure less than atmospheric pressure.

The dyestuff can be applied to the textile material in the form of an aqueous dispersion, the textile material is dried, and then subjected to the dry heat treatment which comprises baking the textile material at temperatures above 100 C., preferably at temperatures between 110 and 240 (3., or subjecting the dried textile material to the action of superheated steam, preferably superheated steam having a temperature of between 110 and 240 C. The dry heat treatment is carried out at pressures below atmospheric pressure and preferably at pressures of between 0.1 and 100 mms. of mercury; If desired, part of the dry heat treatment can be carried out at atmospheric pressure. It is generally found that the dry heat treatment need only be carried out for short periods, and in particular it is found that times of between 30 seconds and 10 minutes are adequate to obtain satisfactory results. If desired the baking treatment can be carried out by means of microwave heating or infra red heating.

The dyestuff, or mixtures of dyestuffs, can be applied to the textile material by dyeing, padding or printing processes using either a dye liquor, padding liquor or print paste containing the dyestuif in the form of'an aqueous dispersion. The said liquors or pastes can contain the conventional additives, such as anionic, non-ionic and/or cationic dispersing agents, urea, sodium m-nitro benzene sulphonate, thickening agents such as alginates or gums, or organic liquids such as benzyl alcohol. When a union of a synthetic textile material and a non-synthetic textile material is being colored by the process of the invention then the said liquor or paste can also contain a dyestuif, usually a water-soluble dyestuff, for the nonsynthetic textile material.

7 As examples of water-insoluble dyestuffs which can be used in the process of the invention there may be mentioned Disperse Dyestuffs such as are described in, for example, pages 1665 to 1742 of the second edition of the Colour Index which was published in 1956, or in British patent specifications Nos. 806,271, 835,819, 840,903, 847,175, 852,396, 852,493, 859,899, 865,328, 872,204, 894,012, 908,656, 909,843, 910,306, 913,856, 919,424, 944,513, 944,722, 953,887 959,816, 960,235, 961,412, 988,629, 976,218, 993,162, 998,858, 1,012,238, 1,012,- 239, 1,016,246, 1,016,651, 1,037,649, 1,020,303, 1,047,- 089, 1,048,250, 1,048,882, 1,049,039, 1,053,830, 1,053,997 and 1,056,354. There can also be used vat dyestuffs such as are described in for example, pages 2419 to 2564 of the second edition of the Colour llndex.

Alternatively the process of the invention can be carried out by a dye transfer technique, in which a print paste containing the water-insoluble dyestufr' is printed onto a cellulose material, such as paper, which is optionally dried, and which is then placed in contact with the synthetic textile material, and the whole subjected to a dry heat treatment at less than atmospheric pressure. This process is advantageously carried out in a continuous manner, in which case the cellulose material and the synthetic textile material are passed together between heated rollers, the pressure round the rollers being maintained at less than atmospheric pressure.

The print pastes used in this process can be either water-based inks or oil-based inks, that is to say the dyestuffs and the other ingredients are dispersed or dissolved in water or in an organic solvent medium, for example in a medium comprising a solution of zinc rosinate in toluene or a solution in ethanol. of a partial ester of pentaerythritol with a mixture or rosin and furmaric acid.

At the conclusion of the process the coloured textile material is preferably rinsed in water and/or given a treatment in an aqueous solution of soap or a synthetic detergent before being dried. In the case of aromatic polyester textile materials it is also preferred to subject the colouredtextile material to a treatment in an alkaline aqueous solution of sodium hydrosulphite before the soap ing treatment in order to remove loosely attached dyestuffs from the surface of the textile material.

As examples of synthetic textile materials which can be coloured by the process of the invention there may be mentioned cellulose acetate and cellulose triacetate textile materials, polyamide textile materials, such as polycaprolactam and polyhexamethyleneadipamide textile materials, polyalkylene textile materials such as polypropylene textile materials, and preferably aromatic polyester materials such as polyethylene terephthalate textile materials. Such textile materials can be in the form of thread, yarn, webs, or woven or knitted fabric. If desired the synthetic textile materials can be in the form of unions with other textile materials, for example polyester/cotton or polyester/wood unions.

By the process of the invention synthetic textile materials are uniformly coloured in up to heavy depths of shade having excellent fastness to the tests commonly applied to such textile materials.

The invention is illustrated but not limited by the following examples in which the parts and percentages are by weight:

EXAMPLE 1 A Woven polyester/cotton blended textile material (containing 67% of polyester and 33% of cotton) is padded through a liquor at 20 C. comprising:

Parts 25% aqueous dispersion of 3-methyl-4-( 6 -thio-f cyanato benZthiazol-Z-ylazo -N N-di ,B-acetoxyethyl)aniline 40 25 aqueous solution of the sodium salt of a partially hydrolysed polyacrylonitrile 20 Aqueous solution containing 14% oleic acid and 29% of a sulphonatedoleate Water 935 and the textile material is then passed between rollers so that it only retains its own weight of the said liquor. The material is dried at 110 C. during 2 minutes and is then subjected to a dry heat treatment comprising baking for 1 minute at 180 C. at atmospheric pressure followed by 2 minutes at 180 C. under a pressure of 13 mms. of mercury.

The colored textile material is then rinsed in water, treated for 15 minutes in an aqueous solution at 50 C. containing 0.2% of sodium hydroxide and 0.2% of sodium hydrosulphite, rinsed in water, soaped for 10 minutes in a 0.2% aqueous solution of a synthetic detergent at 100 C., rinsed again in water and finally dried.

The textile material is colored a red shade having excellent fastness properties, and the polyester portion of the textile material is colored a deeper shade than the polyester portion of a similar textile material which was colored by the same method except that the dry heat treatment was carried out for 3 minutes at 180 C. at atmospheric pressure.

EXAMPLE 2 The procedure of Example 1 is repeated except that the 40 parts of the 25% aqueous dispersion of the dyestutr' used in Example 1 are replaced by 40 parts of a 25% aqueous dispersion of 2-nitrodiphenylamine 4-sulphonanilide, and the baking treatment is carried out at a pressure of 52 mms. of mercury instead of at 13 mms. of mercury.

The textile material is thereby colored a bright yellow shade of excellent fastness properties, and the polyester portion of the textile material is colored a deeper shade than the polyester portion of a similar textile material which was colored by the same method except that the dry heat treatment was carried out for 3 minutes at 180 C. at atmospheric pressure.

EXAMPLE 3 A woven polyester/wool blended textile material (containing 50% of polyester and 50% of wool) is padded through a liquor at C. comprising:

Parts aqueous dispersion of 3-methyl-4-(2 -cyano- 4 -nitrophenylazo N:N di(fi-acetoxyethyl)aniline 40 25 aqueous solution of the sodium salt of a partially hydrolysed polyacrylonitrile 20 Aqueous solution containing 14% oleic acid and 29%: of a sulphonatedoleate 5 Water 935 and the textile material is then passed between rollers so that it only retains its own weight of the said liquor. The

material is dried at C. during 2 minutes and is then subjected to a dry heat treatment comprising baking for 1 minute at. C. at atmospheric pressure followed by 2 minutes at 150 C. under a pressure of 13 mms. of mercury.

The colored textile material is then processed as described in the second paragraph of Example 1.

The textile material is colored a deep rubine shade having excellent fastness properties.

EXAMPLE 4 A woven cotton textile material is padded through a liquor at 20 C. comprising:

Parts 25% aqueous dispersion of 1:4-bis(3 -n1ethyl-4 hydroxyphenylazo) benzene 4O 25% aqueous solution of the sodium salt of a partially hydrolysed polyacrylonitrile 20 Aqueous solution containing 14% oleic acid and 29% of a sulphonatedoleate 5 Water 935 and the textile material is then passed between rollers so that it only retains its own weight of the said liquor.

The textile material is dried at 110 C. and is then pressed in contact with a piece of undyed woven polyester textile material, and the whole then baked for 1 minute at C. at atmospheric pressure followed by 2 minutes at 190 C. at a pressure of 13 mms. of mercury.

The polyester textile material is coloured a much deeper shade by this baking treatment than when the baking treatment is carried out for 3 minutes at 190 C. at atmospheric pressure.

A similar result is obtained when the cotton and polyester are used in the form of yarn which are twisted together before the baking treatment.

EXAMPLE 5 A glossy white art paper is printed, using an engraved roller, with a printing ink comprising:

Parts 25% aqueous dispersion of 2-nitrodiphenylamine- 4-sulphonanilide 40 10% aqueous solution of a starch-ether thickening agent 35 Water 25 and the paper is then dried. The paper is then placed in contact with a woven filament polyester fabric, which is then heated for 10 seconds at 190 C. under a pressure of 70 mms. of mercury. The polyester fabric is thereby printed in a yellow shade, and the colour transfer obtained is much higher than that obtained when the heating is carried out for 15 seconds at 210 C. at atmospheric pressure.

We claim:

1. Process for the colouration of synthetic textile materials and unions containing synthetic textile materials which comprises applying to the textile material a waterinsoluble dyestutf and thereafter subjecting the textile material to a dry heat treatment at a temperature between 110 and 240 C. and at an absolute pressure between '0.1 and 100 mms. of mercury for a period of time in the region of 30 seconds to 10 minutes.

2. Process for the colouration of synthetic textile materials as claimed in claim 1 which comprises applying a print paste containing a water-insoluble dyestuff onto a cellulose material, drying the material, placing it in contact with the synthetic textile material, and the whole is then subjected to a dry heat treatment at a temperature between 110 and 240 C. and at an absolute pressure between 0.1 and 100 mms. of mercury for a period of time in the region of 30 seconds to 10 minutes.

5 6 3. Process as claimed in claim 1 wherein the synthetic OTHER REFERENCES textile material is a polyester textile material. Fox et ah: JSDC, December 1969 i and p. 613. References K. v. Datye: Textilverdlung 4 (1969), No. 7, pp. 562- UNITED STATES PATENTS 5 571. 3:352313 3 5323 fiiiiiIIjIIIijj: 2.215% GEORGE LESMES, Primary Examiner 1,706,827 3/ 1929 Steiger 8-158 T. J. HERBERT, JR., Assistant Examiner 3,219,449 11/1965 Saxe et al. 96-94 BF 3,632,291 1/1972 Defago 8--2.5 10 US. Cl. X.R.

FOREIGN PATENTS 21 176 620,091) 1/1963 Belgium 8-2.5 

